Techniques for resource allocation in an integrated access and backhaul (IAB) system

ABSTRACT

Aspects described herein relate to resource allocation in an integrated access and backhaul (IAB) system. In an example, the aspects include determining, by a central unit (CU), a configuration of not-available (NA) resources for a parent node, wherein the NA resources of the parent node correspond to a set of one or more resources configured at the parent distributed unit (DU) as being unavailable for uplink and downlink communications between the parent DU and a child node; and modifying, by the CU, the first child DU resource configuration to create a modified child DU resource configuration.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims benefit of U.S. Provisional ApplicationNo. 62/977,102 entitled “TECHNIQUES FOR RESOURCE ALLOCATION IN ANINTEGRATED ACCESS AND BACKHAUL (IAB) SYSTEM” filed Feb. 14, 2020, whichis assigned to the assignee hereof and hereby expressly incorporated byreference herein.

BACKGROUND

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to resource allocation inan integrated access and backhaul (IAB) system.

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing the available system resources (e.g., time, frequency, andpower). Examples of such multiple-access systems include code-divisionmultiple access (CDMA) systems, time-division multiple access (TDMA)systems, frequency-division multiple access (FDMA) systems, andorthogonal frequency-division multiple access (OFDMA) systems, andsingle-carrier frequency division multiple access (SC-FDMA) systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. For example, a fifth generation (5G)wireless communications technology (which can be referred to as NR) isenvisaged to expand and support diverse usage scenarios and applicationswith respect to current mobile network generations. In an aspect, 5Gcommunications technology can include: enhanced mobile broadbandaddressing human-centric use cases for access to multimedia content,services and data; ultra-reliable-low latency communications (URLLC)with certain specifications for latency and reliability; and massivemachine type communications, which can allow a very large number ofconnected devices and transmission of a relatively low volume ofnon-delay-sensitive information.

For example, for various communications technology such as, but notlimited to NR, full duplex communication with respect to integratedaccess and backhaul (IAB) implementations may increase transmissionspeed and flexibility but also transmission complexity. Thus,improvements in wireless communication operations may be desired.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

According to an example, a method of wireless communication includingdetermining, by a central unit (CU), a configuration of not-available(NA) resources for a parent node, wherein the NA resources of the parentnode correspond to a set of one or more resources configured at theparent distributed unit (DU) as being unavailable for uplink anddownlink communications between the parent DU and a child node;determining, by the CU, a first child DU resource configuration, whereinthe child DU resource configuration corresponds to a set of one or moreresources configured at the child DU for uplink or downlinkcommunications between the child node and at least one child of thechild node; modifying, by the CU, the first child DU resourceconfiguration to create a modified child DU resource configurationconfigured to provide an indication of the NA resources of the parentnode; and sending, by the CU to the parent DU, the modified child DUresource configuration including the indication of the NA resources ofthe parent node.

In a further example, an apparatus for wireless communication isprovided that includes a transceiver, a memory configured to storeinstructions, and one or more processors communicatively coupled withthe transceiver and the memory. The one or more processors areconfigured to execute the instructions to determine, by a CU, aconfiguration of NA resources for a parent node, wherein the NAresources of the parent node correspond to a set of one or moreresources configured at the parent DU as being unavailable for uplinkand downlink communications between the parent DU and a child node;determine, by the CU, a first child DU resource configuration, whereinthe child DU resource configuration corresponds to a set of one or moreresources configured at the child DU for uplink or downlinkcommunications between the child node and at least one child of thechild node; modify, by the CU, the first child DU resource configurationto create a modified child DU resource configuration configured toprovide an indication of the NA resources of the parent node; and send,by the CU to the parent DU, the modified child DU resource configurationincluding the indication of the NA resources of the parent node.

In another aspect, an apparatus for wireless communication is providedthat includes means for determining, by a CU, a configuration of NAresources for a parent node, wherein the NA resources of the parent nodecorrespond to a set of one or more resources configured at the parent DUas being unavailable for uplink and downlink communications between theparent DU and a child node; means for determining, by the CU, a firstchild DU resource configuration, wherein the child DU resourceconfiguration corresponds to a set of one or more resources configuredat the child DU for uplink or downlink communications between the childnode and at least one child of the child node; means for modifying, bythe CU, the first child DU resource configuration to create a modifiedchild DU resource configuration configured to provide an indication ofthe NA resources of the parent node; and means for sending, by the CU tothe parent DU, the modified child DU resource configuration includingthe indication of the NA resources of the parent node.

In yet another aspect, a non-transitory computer-readable medium isprovided including code executable by one or more processors todetermine, by a CU, a configuration of NA resources for a parent node,wherein the NA resources of the parent node correspond to a set of oneor more resources configured at the parent DU as being unavailable foruplink and downlink communications between the parent DU and a childnode; determine, by the CU, a first child DU resource configuration,wherein the child DU resource configuration corresponds to a set of oneor more resources configured at the child DU for uplink or downlinkcommunications between the child node and at least one child of thechild node; modify, by the CU, the first child DU resource configurationto create a modified child DU resource configuration configured toprovide an indication of the NA resources of the parent node; and send,by the CU to the parent DU, the modified child DU resource configurationincluding the indication of the NA resources of the parent node.

According to another example, a method of wireless communicationincludes receiving, by a parent DU from a CU, a child DU resourceconfiguration for a child node including an indication of NA resources,wherein the NA resources correspond to a set of one or more resourcesconfigured at the parent DU as being unavailable for uplink and downlinkcommunications between the parent DU and the child node of the parentDU; determining, by the parent DU, a set of resources corresponding tothe NA resources indicated in the child DU resource configuration; andrefraining, by the parent DU, from communicating with the child nodewithin the NA resources based on the determining the set of resourcescorresponding to the NA resources.

In a further example, an apparatus for wireless communication isprovided that includes a transceiver, a memory configured to storeinstructions, and one or more processors communicatively coupled withthe transceiver and the memory. The one or more processors areconfigured to execute the instructions to receive, by a parent DU from aCU, a child DU resource configuration for a child node including anindication of NA resources, wherein the NA resources correspond to a setof one or more resources configured at the parent DU as beingunavailable for uplink and downlink communications between the parent DUand the child node of the parent DU; determine, by the parent DU, a setof resources corresponding to the NA resources indicated in the child DUresource configuration; and refrain, by the parent DU, fromcommunicating with the child node within the NA resources based on thedetermining the set of resources corresponding to the NA resources.

In another aspect, an apparatus for wireless communication is providedthat includes means for receiving, by a parent DU from a CU, a child DUresource configuration for a child node including an indication of NAresources, wherein the NA resources correspond to a set of one or moreresources configured at the parent DU as being unavailable for uplinkand downlink communications between the parent DU and the child node ofthe parent DU; determining, by the parent DU, a set of resourcescorresponding to the NA resources indicated in the child DU resourceconfiguration; and refraining, by the parent DU, from communicating withthe child node within the NA resources based on the determining the setof resources corresponding to the NA resources.

In yet another aspect, a non-transitory computer-readable medium isprovided including code executable by one or more processors to receive,by a parent DU from a CU, a child DU resource configuration for a childnode including an indication of NA resources, wherein the NA resourcescorrespond to a set of one or more resources configured at the parent DUas being unavailable for uplink and downlink communications between theparent DU and the child node of the parent DU; determine, by the parentDU, a set of resources corresponding to the NA resources indicated inthe child DU resource configuration; and refrain, by the parent DU, fromcommunicating with the child node within the NA resources based on thedetermining the set of resources corresponding to the NA resources.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction withthe appended drawings, provided to illustrate and not to limit thedisclosed aspects, wherein like designations denote like elements, andin which:

FIG. 1 illustrates an example of a wireless communication system, inaccordance with various aspects of the present disclosure;

FIG. 2 is a block diagram illustrating an example of a network entity(also referred to as a base station), in accordance with various aspectsof the present disclosure;

FIG. 3 is a block diagram illustrating an example of a user equipment(UE), in accordance with various aspects of the present disclosure;

FIG. 4 is a diagram of an example integrated access and backhaul (IAB)system, in accordance with various aspects of the present disclosure;

FIG. 5 is a diagram of an example IAB system for allocating resources inaccordance with various aspects of the present disclosure;

FIG. 6 is a flow chart illustrating an example of a method for wirelesscommunications at a node such as an JAB node in accordance with variousaspects of the present disclosure;

FIG. 7 is a flow chart illustrating an example of a method for wirelesscommunications at a node such as an JAB node in accordance with variousaspects of the present disclosure; and

FIG. 8 is a block diagram illustrating an example of a MIMOcommunication system including a base station and a UE, in accordancewith various aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that such aspect(s) maybe practiced without these specific details.

The described features generally relate to resource allocation in anintegrated access and backhaul (IAB) system. Specifically, base stationsmay include a backhaul interface for communication with a backhaulportion of the network. The backhaul may provide a link between a basestation and a core network, and in some examples, the backhaul mayprovide interconnection between the respective base stations. The corenetwork is a part of a wireless communication system that is generallyindependent of the radio access technology used in the radio accessnetwork. Various types of backhaul interfaces may be employed, such as adirect physical connection, a virtual network, or the like using anysuitable transport network. Some base stations may be configured as TABnodes, where the wireless spectrum may be used both for access links(i.e., wireless links with user equipments (UEs)), and for backhaullinks, which may be referred to as wireless self-backhauling. By usingwireless self-backhauling, rather than requiring each new base stationdeployment to be outfitted with its own hard-wired backhaul connection,the wireless spectrum utilized for communication between the basestation and UE may be leveraged for backhaul communication, enablingfast and easy deployment of highly dense small cell networks.

With respect to resource allocation, current framework supports onlyper-cell resource configuration and a child-node may not be aware abouta not-available (NA) resource configuration of a parent-node. In someimplementations, according to the present aspects, a CU central unit(CU) may provide a per child link resource configuration to eachparent-node distributed unit (parent DU), such as a parent DU havingmultiple cells or two or more parent DUs serving a same child-node. Bybeing aware of the per child link resource configuration, as opposed toa per cell resource configuration, each parent DU may have moreflexibility in scheduling, which may improve efficiency in the use ofnetwork resources. Further, in some implementations, according to thepresent aspects, the child-node may be made aware of the resourceconfigurations associated with the parent-node, which enables thechild-node to avoid attempting to transmit or receive communicationswith the parent-node during such NA resources, thereby saving power,avoiding interference, and/or avoiding incorrectly inferring channelquality and allowing the child-node to instead communicate with itschildren.

As such, it would be desirable to implement such techniques to an IABsystem. Specifically, an IAB-node may have one or more mobileterminations (MTs), and one or more distributed units (DUs) (e.g., andeach DU has one or more cells/sectors). Each entity (MT and/or cell) mayalso have one or more transmission/reception points (TRPs).

In one implementation, the present disclosure includes determining, by aCU, a configuration of not-available (NA) resources for a parent node,wherein the NA resources of the parent node correspond to a set of oneor more resources configured at the parent DU as being unavailable foruplink and downlink communications between the parent DU and a childnode; determining, by the CU, a first child DU resource configuration,wherein the child DU resource configuration corresponds to a set of oneor more resources configured at the child DU for uplink or downlinkcommunications between the child node and at least one child of thechild node; modifying, by the CU, the first child DU resourceconfiguration to create a modified child DU resource configurationconfigured to provide an indication of the NA resources of the parentnode; and sending, by the CU to the parent DU, the modified child DUresource configuration including the indication of the NA resources ofthe parent node.

In another implementation, the present disclosure includes receiving, bya parent DU from a CU, a child DU resource configuration for a childnode including an indication of NA resources, wherein the NA resourcescorrespond to a set of one or more resources configured at the parent DUas being unavailable for uplink and downlink communications between theparent DU and the child node of the parent DU; determining, by theparent DU, a set of resources corresponding to the NA resourcesindicated in the child DU resource configuration; and refraining, by theparent DU, from communicating with the child node within the NAresources based on the determining the set of resources corresponding tothe NA resources.

The described features will be presented in more detail below withreference to FIGS. 1-8 .

As used in this application, the terms “component,” “module,” “system”and the like are intended to include a computer-related entity, such asbut not limited to hardware, software, a combination of hardware andsoftware, or software in execution. For example, a component may be, butis not limited to being, a process running on a processor, a processor,an object, an executable, a thread of execution, a program, and/or acomputer. By way of illustration, both an application running on acomputing device and the computing device can be a component. One ormore components can reside within a process and/or thread of executionand a component can be localized on one computer and/or distributedbetween two or more computers. In addition, these components can executefrom various computer readable media having various data structuresstored thereon. The components can communicate by way of local and/orremote processes such as in accordance with a signal having one or moredata packets, such as data from one component interacting with anothercomponent in a local system, distributed system, and/or across a networksuch as the Internet with other systems by way of the signal. Softwareshall be construed broadly to mean instructions, instruction sets, code,code segments, program code, programs, subprograms, software modules,applications, software applications, software packages, routines,subroutines, objects, executables, threads of execution, procedures,functions, etc., whether referred to as software, firmware, middleware,microcode, hardware description language, or otherwise.

Techniques described herein may be used for various wirelesscommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, andother systems. The terms “system” and “network” may often be usedinterchangeably. A CDMA system may implement a radio technology such asCDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and Aare commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) iscommonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD),etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. ATDMA system may implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA system may implement a radiotechnology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA),Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi),IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM™, etc. UTRA and E-UTRA arepart of Universal Mobile Telecommunication System (UMTS). 3GPP Long TermEvolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS thatuse E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). CDMA2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thetechniques described herein may be used for the systems and radiotechnologies mentioned above as well as other systems and radiotechnologies, including cellular (e.g., LTE) communications over ashared radio frequency spectrum band. The description below, however,describes an LTE/LTE-A system for purposes of example, and LTEterminology is used in much of the description below, although thetechniques are applicable beyond LTE/LTE-A applications (e.g., to fifthgeneration (5G) NR networks or other next generation communicationsystems).

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in other examples.

Various aspects or features will be presented in terms of systems thatcan include a number of devices, components, modules, and the like. Itis to be understood and appreciated that the various systems can includeadditional devices, components, modules, etc. and/or may not include allof the devices, components, modules etc. discussed in connection withthe figures. A combination of these approaches can also be used.

FIG. 1 is a diagram illustrating an example of a wireless communicationssystem and an access network 100. The wireless communications system(also referred to as a wireless wide area network (WWAN)) can includebase stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and/or a5G Core (5GC) 190. The base stations 102, which may also be referred toas network entities, may include macro cells (high power cellular basestation) and/or small cells (low power cellular base station). The macrocells can include base stations. The small cells can include femtocells,picocells, and microcells. In an example, the base stations 102 may alsoinclude gNBs 180, as described further herein.

In one example, some nodes acting as an IAB node, such as base station102/gNB 180, may have a modem 240 and communicating component 242 forallocating resources, as described herein. Though a base station 102/gNB180 is shown as having the modem 240 and communicating component 242,this is one illustrative example, and substantially any node or type ofnode acting as an IAB node may include a modem 240 and communicatingcomponent 242 for providing corresponding functionalities describedherein. In an example, communicating component 242 may include NAresources of parent 252 and NA DU-child resources 254. For example,modem 240 and/or communicating component 242 may determining, by a CU, aconfiguration of NA resources for a parent node, wherein the NAresources of the parent node correspond to a set of one or moreresources configured at the parent DU as being unavailable for uplinkand downlink communications between the parent DU and a child node;determining, by the CU, a first child DU resource configuration, whereinthe child DU resource configuration corresponds to a set of one or moreresources configured at the child DU for uplink or downlinkcommunications between the child node and at least one child of thechild node; modifying, by the CU, the first child DU resourceconfiguration to create a modified child DU resource configurationconfigured to provide an indication of the NA resources of the parentnode; and sending, by the CU to the parent DU, the modified child DUresource configuration including the indication of the NA resources ofthe parent node.

The base stations 102 configured for 4G LTE (which can collectively bereferred to as Evolved Universal Mobile Telecommunications System (UMTS)Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC160 through backhaul links 132 (e.g., using an S1 interface). The basestations 102 configured for 5G NR (which can collectively be referred toas Next Generation RAN (NG-RAN)) may interface with 5GC 190 throughbackhaul links 184. In addition to other functions, the base stations102 may perform one or more of the following functions: transfer of userdata, radio channel ciphering and deciphering, integrity protection,header compression, mobility control functions (e.g., handover, dualconnectivity), inter-cell interference coordination, connection setupand release, load balancing, distribution for non-access stratum (NAS)messages, NAS node selection, synchronization, radio access network(RAN) sharing, multimedia broadcast multicast service (MBMS), subscriberand equipment trace, RAN information management (RIM), paging,positioning, and delivery of warning messages. The base stations 102 maycommunicate directly or indirectly (e.g., through the EPC 160 or 5GC190) with each other over backhaul links 134 (e.g., using an X2interface). The backhaul links 132, 134 and/or 184 may be wired orwireless.

The base stations 102 may wirelessly communicate with one or more UEs104. Each of the base stations 102 may provide communication coveragefor a respective geographic coverage area 110. There may be overlappinggeographic coverage areas 110. For example, the small cell 102′ may havea coverage area 110′ that overlaps the coverage area 110 of one or moremacro base stations 102. A network that includes both small cell andmacro cells may be referred to as a heterogeneous network. Aheterogeneous network may also include Home Evolved Node Bs (eNBs)(HeNBs), which may provide service to a restricted group, which can bereferred to as a closed subscriber group (CSG). The communication links120 between the base stations 102 and the UEs 104 may include uplink(UL) (also referred to as reverse link) transmissions from a UE 104 to abase station 102 and/or downlink (DL) (also referred to as forward link)transmissions from a base station 102 to a UE 104. The communicationlinks 120 may use multiple-input and multiple-output (MIMO) antennatechnology, including spatial multiplexing, beamforming, and/or transmitdiversity. The communication links may be through one or more carriers.The base stations 102/UEs 104 may use spectrum up to Y MHz (e.g., 5, 10,15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrieraggregation of up to a total of Yx MHz (e.g., for x component carriers)used for transmission in the DL and/or the UL direction. The carriersmay or may not be adjacent to each other. Allocation of carriers may beasymmetric with respect to DL and UL (e.g., more or less carriers may beallocated for DL than for UL). The component carriers may include aprimary component carrier and one or more secondary component carriers.A primary component carrier may be referred to as a primary cell (PCell)and a secondary component carrier may be referred to as a secondary cell(SCell).

In another example, certain UEs 104 may communicate with each otherusing device-to-device (D2D) communication link 158. The D2Dcommunication link 158 may use the DL/UL WWAN spectrum. The D2Dcommunication link 158 may use one or more sidelink channels, such as aphysical sidelink broadcast channel (PSBCH), a physical sidelinkdiscovery channel (PSDCH), a physical sidelink shared channel (PSSCH),and a physical sidelink control channel (PSCCH). D2D communication maybe through a variety of wireless D2D communications systems, such as forexample, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi accesspoint (AP) 150 in communication with Wi-Fi stations (STAs) 152 viacommunication links 154 in a 5 GHz unlicensed frequency spectrum. Whencommunicating in an unlicensed frequency spectrum, the STAs 152/AP 150may perform a clear channel assessment (CCA) prior to communicating inorder to determine whether the channel is available.

The small cell 102′ may operate in a licensed and/or an unlicensedfrequency spectrum. When operating in an unlicensed frequency spectrum,the small cell 102′ may employ NR and use the same 5 GHz unlicensedfrequency spectrum as used by the Wi-Fi AP 150. The small cell 102′,employing NR in an unlicensed frequency spectrum, may boost coverage toand/or increase capacity of the access network.

A base station 102, whether a small cell 102′ or a large cell (e.g.,macro base station), may include an eNB, gNodeB (gNB), or other type ofbase station. Some base stations, such as gNB 180 may operate in atraditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies,and/or near mmW frequencies in communication with the UE 104. When thegNB 180 operates in mmW or near mmW frequencies, the gNB 180 may bereferred to as an mmW base station. Extremely high frequency (EHF) ispart of the RF in the electromagnetic spectrum. EHF has a range of 30GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters.Radio waves in the band may be referred to as a millimeter wave. NearmmW may extend down to a frequency of 3 GHz with a wavelength of 100millimeters. The super high frequency (SHF) band extends between 3 GHzand 30 GHz, also referred to as centimeter wave. Communications usingthe mmW/near mmW radio frequency band has extremely high path loss and ashort range. The mmW base station 180 may utilize beamforming 182 withthe UE 104 to compensate for the extremely high path loss and shortrange. A base station 102 referred to herein can include a gNB 180.

The EPC 160 may include a Mobility Management Entity (MME) 162, otherMMEs 164, a Serving Gateway 166, a Multimedia Broadcast MulticastService (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC)170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be incommunication with a Home Subscriber Server (HSS) 174. The MME 162 isthe control node that processes the signaling between the UEs 104 andthe EPC 160. Generally, the MME 162 provides bearer and connectionmanagement. All user Internet protocol (IP) packets are transferredthrough the Serving Gateway 166, which itself is connected to the PDNGateway 172. The PDN Gateway 172 provides UE IP address allocation aswell as other functions. The PDN Gateway 172 and the BM-SC 170 areconnected to the IP Services 176. The IP Services 176 may include theInternet, an intranet, an IP Multimedia Subsystem (IMS), apacket-switched (PS) Streaming Service, and/or other IP services. TheBM-SC 170 may provide functions for MBMS user service provisioning anddelivery. The BM-SC 170 may serve as an entry point for content providerMBMS transmission, may be used to authorize and initiate MBMS BearerServices within a public land mobile network (PLMN), and may be used toschedule MBMS transmissions. The MBMS Gateway 168 may be used todistribute MBMS traffic to the base stations 102 belonging to aMulticast Broadcast Single Frequency Network (MBSFN) area broadcasting aparticular service, and may be responsible for session management(start/stop) and for collecting eMBMS related charging information.

The 5GC 190 may include a Access and Mobility Management Function (AMF)192, other AMFs 193, a Session Management Function (SMF) 194, and a UserPlane Function (UPF) 195. The AMF 192 may be in communication with aUnified Data Management (UDM) 196. The AMF 192 can be a control nodethat processes the signaling between the UEs 104 and the 5GC 190.Generally, the AMF 192 can provide QoS flow and session management. UserInternet protocol (IP) packets (e.g., from one or more UEs 104) can betransferred through the UPF 195. The UPF 195 can provide UE IP addressallocation for one or more UEs, as well as other functions. The UPF 195is connected to the IP Services 197. The IP Services 197 may include theInternet, an intranet, an IP Multimedia Subsystem (IMS), a PS StreamingService, and/or other IP services.

The base station may also be referred to as a gNB, Node B, evolved NodeB (eNB), an access point, a base transceiver station, a radio basestation, a radio transceiver, a transceiver function, a basic serviceset (BSS), an extended service set (ESS), a transmit reception point(TRP), or some other suitable terminology. The base station 102 providesan access point to the EPC 160 or 5GC 190 for a UE 104. Examples of UEs104 include a cellular phone, a smart phone, a session initiationprotocol (SIP) phone, a laptop, a personal digital assistant (PDA), asatellite radio, a positioning system (e.g., satellite, terrestrial), amultimedia device, a video device, a digital audio player (e.g., MP3player), a camera, a game console, a tablet, a smart device, robots,drones, an industrial/manufacturing device, a wearable device (e.g., asmart watch, smart clothing, smart glasses, virtual reality goggles, asmart wristband, smart jewelry (e.g., a smart ring, a smart bracelet)),a vehicle/a vehicular device, a meter (e.g., parking meter, electricmeter, gas meter, water meter, flow meter), a gas pump, a large or smallkitchen appliance, a medical/healthcare device, an implant, asensor/actuator, a display, or any other similar functioning device.Some of the UEs 104 may be referred to as IoT devices (e.g., meters,pumps, monitors, cameras, industrial/manufacturing devices, appliances,vehicles, robots, drones, etc.). IoT UEs may include machine-typecommunication (MTC)/enhanced MTC (eMTC, also referred to as category(CAT)-M, Cat M1) UEs, NB-IoT (also referred to as CAT NB1) UEs, as wellas other types of UEs. In the present disclosure, eMTC and NB-IoT mayrefer to future technologies that may evolve from or may be based onthese technologies. For example, eMTC may include FeMTC (further eMTC),eFeMTC (enhanced further eMTC), mMTC (massive MTC), etc., and NB-IoT mayinclude eNB-IoT (enhanced NB-IoT), FeNB-IoT (further enhanced NB-IoT),etc. The UE 104 may also be referred to as a station, a mobile station,a subscriber station, a mobile unit, a subscriber unit, a wireless unit,a remote unit, a mobile device, a wireless device, a wirelesscommunications device, a remote device, a mobile subscriber station, anaccess terminal, a mobile terminal, a wireless terminal, a remoteterminal, a handset, a user agent, a mobile client, a client, or someother suitable terminology.

Turning now to FIGS. 2-8 , aspects are depicted with reference to one ormore components and one or more methods that may perform the actions oroperations described herein, where aspects in dashed line may beoptional. Although the operations described below in FIGS. 6 and 7 arepresented in a particular order and/or as being performed by an examplecomponent, it should be understood that the ordering of the actions andthe components performing the actions may be varied, depending on theimplementation. Moreover, it should be understood that the followingactions, functions, and/or described components may be performed by aspecially-programmed processor, a processor executingspecially-programmed software or computer-readable media, or by anyother combination of a hardware component and/or a software componentcapable of performing the described actions or functions.

Referring to FIG. 2 , one example of an implementation of a node actingas an IAB node, such as base station 102 (e.g., a base station 102and/or gNB 180, as described above) may include a variety of components,some of which have already been described above and are describedfurther herein, including components such as one or more processors 212and memory 216 and transceiver 202 in communication via one or morebuses 244, which may operate in conjunction with modem 240 and/orcommunicating component 242 for resource allocation.

In an aspect, the one or more processors 212 can include a modem 240and/or can be part of the modem 240 that uses one or more modemprocessors. Thus, the various functions related to communicatingcomponent 242 may be included in modem 240 and/or processors 212 and, inan aspect, can be executed by a single processor, while in otheraspects, different ones of the functions may be executed by acombination of two or more different processors. For example, in anaspect, the one or more processors 212 may include any one or anycombination of a modem processor, or a baseband processor, or a digitalsignal processor, or a transmit processor, or a receiver processor, or atransceiver processor associated with transceiver 202. In other aspects,some of the features of the one or more processors 212 and/or modem 240associated with communicating component 242 may be performed bytransceiver 202.

Also, memory 216 may be configured to store data used herein and/orlocal versions of applications 275 or communicating component 242 and/orone or more of its subcomponents being executed by at least oneprocessor 212. Memory 216 can include any type of computer-readablemedium usable by a computer or at least one processor 212, such asrandom access memory (RAM), read only memory (ROM), tapes, magneticdiscs, optical discs, volatile memory, non-volatile memory, and anycombination thereof. In an aspect, for example, memory 216 may be anon-transitory computer-readable storage medium that stores one or morecomputer-executable codes defining communicating component 242 and/orone or more of its subcomponents, and/or data associated therewith, whenbase station 102 is operating at least one processor 212 to executecommunicating component 242 and/or one or more of its subcomponents.

Transceiver 202 may include at least one receiver 206 and at least onetransmitter 208. Receiver 206 may include hardware and/or softwareexecutable by a processor for receiving data, the code comprisinginstructions and being stored in a memory (e.g., computer-readablemedium). Receiver 206 may be, for example, a radio frequency (RF)receiver. In an aspect, receiver 206 may receive signals transmitted byat least one base station 102. Additionally, receiver 206 may processsuch received signals, and also may obtain measurements of the signals,such as, but not limited to, Ec/Io, signal-to-noise ratio (SNR),reference signal received power (RSRP), received signal strengthindicator (RSSI), etc. Transmitter 208 may include hardware and/orsoftware executable by a processor for transmitting data, the codecomprising instructions and being stored in a memory (e.g.,computer-readable medium). A suitable example of transmitter 208 mayincluding, but is not limited to, an RF transmitter.

Moreover, in an aspect, base station 102 may include RF front end 288,which may operate in communication with one or more antennas 265 andtransceiver 202 for receiving and transmitting radio transmissions, forexample, wireless communications transmitted by at least one basestation 102 or wireless transmissions transmitted by UE 104. RF frontend 288 may be connected to one or more antennas 265 and can include oneor more low-noise amplifiers (LNAs) 290, one or more switches 292, oneor more power amplifiers (PAs) 298, and one or more filters 296 fortransmitting and receiving RF signals. The antennas 265 may include oneor more antennas, antenna elements, and/or antenna arrays.

In an aspect, LNA 290 can amplify a received signal at a desired outputlevel. In an aspect, each LNA 290 may have a specified minimum andmaximum gain values. In an aspect, RF front end 288 may use one or moreswitches 292 to select a particular LNA 290 and its specified gain valuebased on a desired gain value for a particular application.

Further, for example, one or more PA(s) 298 may be used by RF front end288 to amplify a signal for an RF output at a desired output powerlevel. In an aspect, each PA 298 may have specified minimum and maximumgain values. In an aspect, RF front end 288 may use one or more switches292 to select a particular PA 298 and its specified gain value based ona desired gain value for a particular application.

Also, for example, one or more filters 296 can be used by RF front end288 to filter a received signal to obtain an input RF signal. Similarly,in an aspect, for example, a respective filter 296 can be used to filteran output from a respective PA 298 to produce an output signal fortransmission. In an aspect, each filter 296 can be connected to aspecific LNA 290 and/or PA 298. In an aspect, RF front end 288 can useone or more switches 292 to select a transmit or receive path using aspecified filter 296, LNA 290, and/or PA 298, based on a configurationas specified by transceiver 202 and/or processor 212.

As such, transceiver 202 may be configured to transmit and receivewireless signals through one or more antennas 265 via RF front end 288.In an aspect, transceiver may be tuned to operate at specifiedfrequencies such that UE 104 can communicate with, for example, one ormore base stations 102 or one or more cells associated with one or morebase stations 102. In an aspect, for example, modem 240 can configuretransceiver 202 to operate at a specified frequency and power levelbased on the UE configuration of the UE 104 and the communicationprotocol used by modem 240.

In an aspect, modem 240 can be a multiband-multimode modem, which canprocess digital data and communicate with transceiver 202 such that thedigital data is sent and received using transceiver 202. In an aspect,modem 240 can be multiband and be configured to support multiplefrequency bands for a specific communications protocol. In an aspect,modem 240 can be multimode and be configured to support multipleoperating networks and communications protocols. In an aspect, modem 240can control one or more components of UE 104 (e.g., RF front end 288,transceiver 202) to enable transmission and/or reception of signals fromthe network based on a specified modem configuration. In an aspect, themodem configuration can be based on the mode of the modem and thefrequency band in use. In another aspect, the modem configuration can bebased on UE configuration information associated with UE 104 as providedby the network during cell selection and/or cell reselection.

In an aspect, the processor(s) 212 may correspond to one or more of theprocessors described in connection with the UE in FIG. 8 . Similarly,the memory 216 may correspond to the memory described in connection withthe UE in FIG. 8 .

Referring to FIG. 3 , one example of an implementation of UE 104 mayinclude a variety of components, some of which have already beendescribed above and are described further herein, including componentssuch as one or more processors 312 and memory 316 and transceiver 302 incommunication via one or more buses 344, which may operate inconjunction with modem 340.

The transceiver 302, receiver 306, transmitter 308, one or moreprocessors 312, memory 316, applications 375, buses 344, RF front end388, LNAs 390, switches 392, filters 396, PAs 398, and one or moreantennas 365 may be the same as or similar to the correspondingcomponents of base station 102, as described above, but configured orotherwise programmed for base station operations as opposed to basestation operations.

In an aspect, the processor(s) 312 may correspond to one or more of theprocessors described in connection with the base station in FIG. 8 .Similarly, the memory 316 may correspond to the memory described inconnection with the base station in FIG. 8 .

Further, FIG. 4 is a diagram of an uplink and downlink communicationscheme in an IAB system 400, as described herein. In one example, theIAB system 400 may include an IAB node 404, which may be similar to orthe same as the base station 102. The IAB system 400 may further includea parent node 402, a child node 406, and a UE 104. For example, in anIAB system, an IAB node 404 can transmit uplink data towards the parentnode 402, and receive the uplink data from the UE 104 and/or child node406. The IAB node 404 may also transmit downlink data towards the childnode 406, and receive the downlink data from the parent node 402.

In some aspects, the IAB node 404 may host two NR functions: (i) a MT408, used to maintain the wireless backhaul connection towards anupstream IAB-node or IAB-donor, and (ii) a DU 410 to provide accessconnection to the UEs or the downstream MTs of other IAB-nodes. The DU410 may connect to a CU hosted by the IAB-donor by means of the NR F1interface running over the wireless backhaul link. Therefore, in theaccess of IAB nodes and donors there may be a coexistence of twointerfaces, i.e., the Uu interface (e.g., between the UEs and the DU ofthe gNBs) and the aforementioned F1 interface.

The IAB node 404 may include the communicating component 242, which maybe configured to determine a spatial relation between a firstcommunication of a DU 410 entity and a second communication of one ofthe DU entity or a co-located MT 408 entity. The IAB node 404 mayfurther configure a beam of at least one of the MT 408 or the DU 410based on the determined spatial relation, and communicate using the beamwith at least one entity.

In an aspect, an IAB-node MT, e.g., a UE, may be provided time-divisionduplexing (TDD) configurations and slot format indications (SFI).Specifically, the IAB-node MT is provided the same TDD configurations(e.g., TDD_UL_DL_ConfigurationCommon broadcasted in SIB1) as UEs, andmay additionally be provided dedicated TDD configurations (e.g.,TDD_UL_DL_ConfigDedicated_IAB_MT, similar to Rel-15TDD_UL_DL_ConfigDedicated, but also supports new slot configurationsthat begin with uplink symbols). The IAB-MT may also be provided SFI(via DCI). However, the SFI table has been extended for IAB to includenew slot formats.

In an aspect, an IAB-node DU may be provided, by the CU, an indicationfor a slot format over a number of slots byIAB-DU-Resource-Configuration. The DU-Resource-Configuration indicatesboth the downlink/uplink/flexible (D/U/F) type of resources, as well ashard/soft/not-available (H/S/NA). The indication of D/U/F resources inthe semi-static DU resource configuration includes the following: theflexibility to configure all of the slot patterns and formats supportedby the existing Rel-15 TDD-UL-DL-Config radio resource control (RRC)configurations and slot format table; and new slot formats defined onlyfor IAB nodes (DU and MTs) which begin with uplink slots, uplinksymbols, or flexible symbols. Additionally, H/S/NA attributes for theper-cell DU resource configuration are explicitly indicated per-resourcetype (D/U/F) in each slot.

Further, in an example, a parent IAB node/donor may be provided with thefull D/U/F and H/S/NA resource configuration of each child IAB-DU. Thisextra information has three main uses. First, a parent-node with theknowledge of a child DU resource configuration (and the multiplexingcapabilities of the child) may avoid potential conflicts. For example,if the same set of resources are allocated as hard to both parent-nodeand the child-node then the parent-node may avoid communicating with thechild over those resources. Second, a parent-node will know theconfiguration of soft resources of the child for sending theavailability indication. Third, a child-node may need a guard periodwhen switching between communicating over parent-backhaul (BH) link (MTTX or MT RX), and communicating over the child-links (DU TX or DU RX).Rel-16 IAB introduced new signaling where a child-node may request forguard symbols (per switch type), and parent-node may indicate the amountof guard symbols (per switch type) it is willing to provide. Todetermine the location and amount of such guard symbols, the childresource configuration should be known by the parent-node.

FIG. 5 is a diagram of resource allocation in an IAB system 500, asdescribed herein. In one example, the IAB system 500 may include an IABnode, which may be similar to or the same as the base station 102. IABsystem 500 may include a CU 502, DU 504, one or more child DUs 506, 508,510 and child nodes 1, 2, and 3.

In an aspect, one drawback of the current framework is that the currentframework supports only per-cell resource configuration. That is, a DU504 may comprise multiple cells, and for each cell the DU is provided aD/U/F and H/S/NA resource configuration. Accordingly, being able toconfigure resources per child-link provides a flexibility to the networkto better utilize the resources. As such, with the knowledge of thechild resource allocation, various per-child resource configurationscould be effectively created at the parent-node. For example,

-   -   Parent DU resource configuration: [slot n, slot n+1]=[H, H]    -   Child 1 DU 506: [slot n, slot n+1]=[H, NA]    -   Child 2 DU 508: [slot n, slot n+1]=[NA, H]

The parent DU 504, with the knowledge of child 1 506 and 2 508 allocatedresource, may infer that:

-   -   For communicating with child 1 506: [slot n, slot n+1]=[NA, H]    -   For communicating with child 2 508: [slot n, slot n+1]=[H, NA]

In an aspect, for a multi-parent configuration, child C is connected totwo parent nodes P1 and P2, and due to a half-duplex constraint, C mayuse time-division multiplexing (TDM) to communicate with P1, P2, and itsown children. For example, C may be configured to communicate with P1and P2 during slots n and n+1 respectively, and with own children duringslot n+2: C's DU resource configuration: [slot n, slot n+1, slotn+2]=[NA, NA, H].

Further, parent node 1 (P1) and parent node 2 (P2) may have additionalchildren, and may provide resources to these additional resources:

-   -   P1 DU resource configuration: [slot n, slot n+1, slot n+2]=[H,        H, H]    -   P2 DU resource configuration: [slot n, slot n+1, slot n+2]=[H,        H, H]

P1 may be configured for communication with child C: [slot n, slot n+1,slot n+2]=[H, NA, NA], which cannot be inferred from the knowledge ofthe DU resource configuration of CU of [NA, NA, H]. (b/c [H, H, H]−[NA,NA, H]:=[H, H, NA]). Thus, the present disclosure provides apparatus andmethods that enable allocating resources per child-link and notper-cell.

In another aspect, another drawback of the current framework is that thea child-node is not aware of an NA resource configuration of acorresponding parent-node (parent DU). If some resources are NA for theparent-node, then no DL/UL communication may occur between the child andparent-node within those resources. Without the knowledge of allocatedresources of the parent-node, the child may attempt to receive (RX) ortransmit (TX) signals within NA resources. This may result inimplications, such as, but not limited to, power consumption,interference, and incorrect inference of the channel/link quality at thechild-node. Furthermore, such resources may have been used for othercommunications of the child-node (e.g. communication withgrand-children, or with another parent). Accordingly, to the presentdisclosure provides apparatus and methods that enable providing achild-node with (or at least part of) H/S/NA configuration of theparent-node.

Turning now to FIGS. 6 and 7 , aspects are depicted with reference toone or more components and one or more methods that may perform theactions or operations described herein, where aspects in dashed line maybe optional. Although the operations described below in FIGS. 6 and 7are presented in a particular order and/or as being performed by anexample component, it should be understood that the ordering of theactions and the components performing the actions may be varied,depending on the implementation. Moreover, it should be understood thatthe following actions, functions, and/or described components may beperformed by reference to one or more components of FIGS. 1, 2, 4, 5and/or 8 , as described herein, a specially-programmed processor, aprocessor executing specially-programmed software or computer-readablemedia, or by any other combination of a hardware component and/or asoftware component capable of performing the described actions orfunctions.

FIG. 6 illustrates a flow chart of an example of a method 600 forwireless communication at a node, which may be an IAB node, and morespecifically, resource allocation in an IAB system. In an example, abase station 102 can perform the functions described in method 600 usingone or more of the components described in FIGS. 1, 2, 4, 5, and 8 .

At block 602, the method 600 may determine, by a CU, a configuration ofNA resources for a parent node, wherein the NA resources of the parentnode correspond to a set of one or more resources configured at theparent DU as being unavailable for uplink and downlink communicationsbetween the parent DU and a child node. In an aspect, the communicatingcomponent 242, e.g., in conjunction with processor(s) 212, memory 216,and/or transceiver 202, may be configured to determine, by a CU, aconfiguration of NA resources for a parent node, wherein the NAresources of the parent node correspond to a set of one or moreresources configured at the parent DU as being unavailable for uplinkand downlink communications between the parent DU and a child node. Inone example, the data can be associated with a priority level. Thus, thebase station 102, the processor(s) 212, the communicating component 242or one of its subcomponents may define the means for determining, by aCU, a configuration of NA resources for a parent node, wherein the NAresources of the parent node correspond to a set of one or moreresources configured at the parent DU as being unavailable for uplinkand downlink communications between the parent DU and a child node. Forexample, in an aspect, the base station 102 and/or the communicationcomponent 242 may process a signal to determine a configuration of NAresources for a parent node, and/or performs other signal processes suchas described above in FIG. 2 .

At block 604, the method 600 may determine, by the CU, a first child DUresource configuration, wherein the child DU resource configurationcorresponds to a set of one or more resources configured at the child DUfor uplink or downlink communications between the child node and atleast one child of the child node. In an aspect, the communicatingcomponent 242, e.g., in conjunction with processor(s) 212, memory 216,and/or transceiver 202, may be configured to determine, by the CU, afirst child DU resource configuration, wherein the child DU resourceconfiguration corresponds to a set of one or more resources configuredat the child DU for uplink or downlink communications between the childnode and at least one child of the child node. Thus, the base station102, the processor(s) 212, the communicating component 242 or one of itssubcomponents may define the means for determining, by the CU, a firstchild DU resource configuration, wherein the child DU resourceconfiguration corresponds to a set of one or more resources configuredat the child DU for uplink or downlink communications between the childnode and at least one child of the child node. For example, in anaspect, the base station 102 and/or the communication component 242 mayprocess a signal to determine a first child DU resource configuration,and/or performs other signal processes such as described above in FIG. 2.

At block 606, the method 600 may modify, by the CU, the first child DUresource configuration to create a modified child DU resourceconfiguration configured to provide an indication of the NA resources ofthe parent node. In an aspect, the communicating component 242, e.g., inconjunction with processor(s) 212, memory 216, and/or transceiver 202,may be configured to modify, by the CU, the first child DU resourceconfiguration to create a modified child DU resource configurationconfigured to provide an indication of the NA resources of the parentnode. Thus, the base station 102, the processor(s) 212, thecommunicating component 242 or one of its subcomponents may define themeans for modifying, by the CU, the first child DU resourceconfiguration to create a modified child DU resource configurationconfigured to provide an indication of the NA resources of the parentnode. For example, in an aspect, the base station 102 and/or thecommunication component 242 may process a signal, such as the firstchild DU resource configuration, to modify a modified child DU resourceconfiguration, and/or performs other signal processes such as describedabove in FIG. 2 .

At block 608, the method 600 may send, by the CU to the parent DU, themodified child DU resource configuration including the indication of theNA resources of the parent node. In an aspect, the communicatingcomponent 242, e.g., in conjunction with processor(s) 212, memory 216,and/or transceiver 202, may be configured to send, by the CU to theparent DU, the modified child DU resource configuration including theindication of the NA resources of the parent node. Thus, the basestation 102, the processor(s) 212, the communicating component 242 orone of its subcomponents may define the means for sending, by the CU tothe parent DU, the modified child DU resource configuration includingthe indication of the NA resources of the parent node. For example, inan aspect, the base station 102 and/or the communication component 242may process a signal, such as the modified child DU resourceconfiguration, and transmit the modified child DU resourceconfiguration, and/or performs other signal processes such as describedabove in FIG. 2 .

In some aspects of method 600, the communicating component 242, e.g., inconjunction with processor(s) 212, memory 216, and/or transceiver 202may be configured for sending, by the CU, the first child DU resourceconfiguration to the child node.

In some aspects, the modified child DU resource configuration isdifferent from the first child DU resource configuration.

In some aspects, the modified child DU resource configuration includesan indication of downlink/uplink/flexible (D/U/F) resources andhard/soft/not-available (H/S/NA) resources.

In some aspects, the modified child DU resource configuration providesan indication of the NA resources of the parent node by indicating thecorresponding resources as hard resources to the parent DU.

In some aspects, the modified child DU resource configuration providesan indication of the NA resources of the parent node by indicating aninvalid slot format for the corresponding resources.

In some aspect of method 600, the communicating component 242, e.g., inconjunction with processor(s) 212, memory 216, and/or transceiver 202may be configured for selecting a pattern for one or more attributes ofthe modified child DU resource configuration, wherein the patternindicates a resource type for a set of symbols and slots.

In some aspects of method 600, the communicating component 242, e.g., inconjunction with processor(s) 212, memory 216, and/or transceiver 202may be configured for selecting a slot format to be used by the parentDU to determine one or more guard symbols, wherein the slot formatcorresponds to a valid format indicating to the parent DU to provide theone or more guard symbols for the child node during switching from theparent DU to a second parent DU; and wherein the modified child DUresource configuration indicates the slot format to enable the parent DUto implicitly determine a switch type to allow the child node tocommunicate with a second parent DU.

In some aspects, the modified child DU resource configuration indicatesan invalid slot format for one or more slots and includes the one ormore slots indicated as hard resources to indicate to the parent DU thatthe child node will not have any communication with children nodes ofthe child node or another parent DU.

In some aspects, the modified child DU resource configuration indicatesan invalid slot format for one or more slots and includes the one ormore slots indicated as not-available resources to indicate to theparent DU that the child node will be in communication with anotherparent DU.

In some aspects, the modified child DU resource configuration includes areserved resource type indicating to a parent-node that one or moreresources are reserved and unavailable for the parent-node tocommunicate with the child-node.

FIG. 7 illustrates a flow chart of an example of a method 700 forwireless communication at a node, which may be an IAB node, and morespecifically, resource allocation in an IAB system. In an example, abase station 102 can perform the functions described in method 700 usingone or more of the components described in FIGS. 1, 2, 4, 5, and 8 .

At block 702, the method 700 may receive, by a parent DU from a CU, achild DU resource configuration for a child node including an indicationof NA resources, wherein the NA resources correspond to a set of one ormore resources configured at the parent DU as being unavailable foruplink and downlink communications between the parent DU and the childnode of the parent DU. In an aspect, the communicating component 242,e.g., in conjunction with processor(s) 212, memory 216, and/ortransceiver 202, may be configured to receive, by a parent DU from a CU,a child DU resource configuration for a child node including anindication of NA resources, wherein the NA resources correspond to a setof one or more resources configured at the parent DU as beingunavailable for uplink and downlink communications between the parent DUand the child node of the parent DU. Thus, the base station 102, theprocessor(s) 212, the communicating component 242 or one of itssubcomponents may define the means for receiving, by a parent DU from aCU, a child DU resource configuration for a child node including anindication of NA resources, wherein the NA resources correspond to a setof one or more resources configured at the parent DU as beingunavailable for uplink and downlink communications between the parent DUand the child node of the parent DU. For example, in an aspect, the basestation 102 and/or the communication component 242 may receive a signal,such as a child DU resource configuration for a child node, and/orperforms other signal processes such as described above in FIG. 2 .

At block 704, the method 700 may determine, by the parent DU, a set ofresources corresponding to the NA resources indicated in the child DUresource configuration. In an aspect, the communicating component 242,e.g., in conjunction with processor(s) 212, memory 216, and/ortransceiver 202, may be configured to determine, by the parent DU, a setof resources corresponding to the NA resources indicated in the child DUresource configuration. Thus, the base station 102, the processor(s)212, the communicating component 242 or one of its subcomponents maydefine the means for determining, by the parent DU, a set of resourcescorresponding to the NA resources indicated in the child DU resourceconfiguration. For example, in an aspect, the base station 102 and/orthe communication component 242 may process a signal, such as the childDU resource configuration, to determine a set of resources, and/orperforms other signal processes such as described above in FIG. 2 .

At block 706, the method 700 may refrain, by the parent DU, fromcommunicating with the child node within the NA resources based on thedetermining the set of resources corresponding to the NA resources. Inan aspect, the communicating component 242, e.g., in conjunction withprocessor(s) 212, memory 216, and/or transceiver 202, may be configuredto refrain, by the parent DU, from communicating with the child nodewithin the NA resources based on the determining the set of resourcescorresponding to the NA resources. Thus, the base station 102, theprocessor(s) 212, the communicating component 242 or one of itssubcomponents may define the means for refraining, by the parent DU,from communicating with the child node within the NA resources based onthe determining the set of resources corresponding to the NA resources.For example, in an aspect, the base station 102 and/or the communicationcomponent 242 may process a signal, such as a determination of the setof resources corresponding to the NA resources, to refrain fromcommunicating with the child node, and/or performs other signalprocesses such as described above in FIG. 2 .

In some aspects, the child DU resource configuration corresponds to amodified child DU resource configuration configured to indicate the NAresources to the parent DU.

In some aspects, the modified child DU resource configuration isdifferent from a corresponding first child DU resource configurationprovided to the child node.

In some aspects, the modified child DU resource configuration includesan indication of downlink/uplink/flexible (D/U/F) resources andhard/soft/not-available (H/S/NA) resources.

In some aspects, the modified child DU resource configuration includesone or more symbols indicated as hard NA resources to the parent DU.

In some aspects, the modified child DU resource configuration indicatesan invalid slot format for one or more slots.

In some aspects of method 700, the communicating component 242, e.g., inconjunction with processor(s) 212, memory 216, and/or transceiver 202may be configured for selecting a pattern for one or more attributes ofthe modified child DU resource configuration, wherein the patternindicates a resource type for a set of symbols and slots.

In some aspects of method 700, the communicating component 242, e.g., inconjunction with processor(s) 212, memory 216, and/or transceiver 202may be configured for receiving, by parent DU from the CU, a slot formatto enable the parent DU to implicitly determine a switch type to allowthe child node to communicate with a second parent DU; and determiningone or more guard symbols based on the slot format, wherein the slotformat corresponds to a valid format indicating to the parent DU toprovide the one or more guard symbols for the child node duringswitching from the parent DU to a second parent DU.

In some aspects, the modified child DU resource configuration indicatesan invalid slot format for one or more slots and includes one or moreslots indicated as hard resources to the parent DU to indicate to theparent DU that the child node will not have any communication withchildren nodes of the child node or another parent DU.

In some aspects, the modified child DU resource configuration indicatesan invalid slot format for one or more slots and includes one or moreslots indicated as not-available resources to the parent DU to indicateto the parent DU that the child node will be in communication withanother parent DU.

In some aspects, the modified child DU resource configuration includes areserved resource type indicating to a parent-node that one or moreresources are reserved and unavailable for the parent-node tocommunicate with the child-node.

FIG. 8 is a block diagram of a MIMO communication system 800 including abase station 102, which may be acting as an IAB node or a parent node,and a UE 104. The MIMO communication system 800 may illustrate aspectsof the wireless communication access network 80 described with referenceto FIG. 1 . The base station 102 may be an example of aspects of thebase station 102 described with reference to FIG. 1 . The base station102 may be equipped with antennas 834 and 835, and the UE 104 may beequipped with antennas 852 and 853. In the MIMO communication system800, the base station 102 may be able to send data over multiplecommunication links at the same time. Each communication link may becalled a “layer” and the “rank” of the communication link may indicatethe number of layers used for communication. For example, in a 2×2 MIMOcommunication system where base station 102 transmits two “layers,” therank of the communication link between the base station 102 and the UE104 is two.

At the base station 102, a transmit (Tx) processor 820 may receive datafrom a data source. The transmit processor 820 may process the data. Thetransmit processor 1020 may also generate control symbols or referencesymbols. A transmit MIMO processor 830 may perform spatial processing(e.g., precoding) on data symbols, control symbols, or referencesymbols, if applicable, and may provide output symbol streams to thetransmit modulator/demodulators 832 and 833. Each modulator/demodulator832 through 833 may process a respective output symbol stream (e.g., forOFDM, etc.) to obtain an output sample stream. Eachmodulator/demodulator 832 through 833 may further process (e.g., convertto analog, amplify, filter, and upconvert) the output sample stream toobtain a DL signal. In one example, DL signals frommodulator/demodulators 832 and 833 may be transmitted via the antennas834 and 835, respectively.

The UE 104 may be an example of aspects of the UEs 104 described withreference to FIGS. 1 and 2 . At the UE 104, the UE antennas 852 and 853may receive the DL signals from the base station 102 and may provide thereceived signals to the modulator/demodulators 854 and 855,respectively. Each modulator/demodulator 854 through 855 may condition(e.g., filter, amplify, downconvert, and digitize) a respective receivedsignal to obtain input samples. Each modulator/demodulator 854 through855 may further process the input samples (e.g., for OFDM, etc.) toobtain received symbols. A MIMO detector 856 may obtain received symbolsfrom the modulator/demodulators 854 and 855, perform MIMO detection onthe received symbols, if applicable, and provide detected symbols. Areceive (Rx) processor 858 may process (e.g., demodulate, deinterleave,and decode) the detected symbols, providing decoded data for the UE 104to a data output, and provide decoded control information to a processor880, or memory 882.

The processor 880 may in some cases execute stored instructions toinstantiate a communicating component 242 (see e.g., FIGS. 1 and 2 ).

On the uplink (UL), at the UE 104, a transmit processor 864 may receiveand process data from a data source. The transmit processor 864 may alsogenerate reference symbols for a reference signal. The symbols from thetransmit processor 864 may be precoded by a transmit MIMO processor 866if applicable, further processed by the modulator/demodulators 854 and855 (e.g., for SC-FDMA, etc.), and be transmitted to the base station102 in accordance with the communication parameters received from thebase station 102. At the base station 102, the UL signals from the UE104 may be received by the antennas 834 and 835, processed by themodulator/demodulators 832 and 833, detected by a MIMO detector 836 ifapplicable, and further processed by a receive processor 838. Thereceive processor 838 may provide decoded data to a data output and tothe processor 840 or memory 842.

The components of the UE 104 may, individually or collectively, beimplemented with one or more ASICs adapted to perform some or all of theapplicable functions in hardware. Each of the noted modules may be ameans for performing one or more functions related to operation of theMIMO communication system 800. Similarly, the components of the basestation 102 may, individually or collectively, be implemented with oneor more ASICs adapted to perform some or all of the applicable functionsin hardware. Each of the noted components may be a means for performingone or more functions related to operation of the MIMO communicationsystem 800.

Some Further Example Clauses

Implementation examples are described in the following numbered clauses:

1. A method of wireless communication, comprising:

determining, by a central unit (CU), a configuration of not-available(NA) resources for a parent node, wherein the NA resources of the parentnode correspond to a set of one or more resources configured at theparent distributed unit (DU) as being unavailable for uplink anddownlink communications between the parent DU and a child node, and

a first child DU resource configuration, wherein the child DU resourceconfiguration corresponds to a set of one or more resources configuredat the child node DU for uplink or downlink communications between thechild node and at least one child of the child node;

modifying, by the CU, the first child DU resource configuration tocreate a modified child DU resource configuration configured to providean indication of the NA resources of the parent node; and

sending, by the CU to the parent DU, the modified child DU resourceconfiguration including the indication of the NA resources of the parentnode.

2. The method of any preceding clause, further comprises sending, by theCU, the first child DU resource configuration to the child node.

3. The method of any preceding clause, wherein the modified child DUresource configuration is different from the first child DU resourceconfiguration.

4. The method of any preceding clause, wherein the modified child DUresource configuration includes an indication ofdownlink/uplink/flexible (D/U/F) resources and hard/soft/not-available(H/S/NA) resources.

5. The method of any preceding clause, wherein the modified child DUresource configuration provides an indication of the NA resources of theparent node by indicating the corresponding resources as hard resourcesto the parent DU.

6. The method of any preceding clause, wherein the modified child DUresource configuration provides an indication of the NA resources of theparent node by indicating an invalid slot format for the correspondingresources.

7. The method of any preceding clause, further comprising selecting apattern for one or more attributes of the modified child DU resourceconfiguration, wherein the pattern indicates a resource type for a setof symbols and slots.

8. The method of any preceding clause, further comprising:

selecting a slot format to be used by the parent DU to determine one ormore guard symbols, wherein the slot format corresponds to a validformat indicating to the parent DU to provide the one or more guardsymbols for the child node during switching from the parent DU to asecond parent DU; and

wherein the modified child DU resource configuration indicates the slotformat to enable the parent DU to implicitly determine a switch type toallow the child node to communicate with a second parent DU.

9. The method of any preceding clause, wherein the modified child DUresource configuration indicates an invalid slot format for one or moreslots and includes the one or more slots indicated as hard resources toindicate to the parent DU that the child node will not have anycommunication with children nodes of the child node or another parentDU.

10. The method of any preceding clause, wherein the modified child DUresource configuration indicates an invalid slot format for one or moreslots and includes the one or more slots indicated as not-availableresources to indicate to the parent DU that the child node will be incommunication with another parent DU.

11. The method of any preceding clause, the modified child DU resourceconfiguration includes a reserved resource type indicating to aparent-node that one or more resources are reserved and unavailable forthe parent-node to communicate with the child-node.

12. A method of wireless communications, comprising:

receiving, by a parent distributed unit (DU) from a central unit (CU), achild DU resource configuration for a child node including an indicationof not-available (NA) resources, wherein the NA resources correspond toa set of one or more resources configured at the parent DU as beingunavailable for uplink and downlink communications between the parent DUand the child node of the parent DU;

determining, by the parent DU, a set of resources corresponding to theNA resources indicated in the child DU resource configuration; and

refraining, by the parent DU, from communicating with the child nodewithin the NA resources based on the determining the set of resourcescorresponding to the NA resources.

13. The method of any preceding clause, wherein the child DU resourceconfiguration corresponds to a modified child DU resource configurationconfigured to indicate the NA resources to the parent DU.

14. The method of any preceding clause, wherein the modified child DUresource configuration is different from a corresponding first child DUresource configuration provided to the child node.

15. The method of any preceding clause, wherein the modified child DUresource configuration includes an indication ofdownlink/uplink/flexible (D/U/F) resources and hard/soft/not-available(H/S/NA) resources.

16. The method of any preceding clause, wherein the modified child DUresource configuration includes one or more symbols indicated as hard NAresources to the parent DU.

17. The method of any preceding clause, wherein the modified child DUresource configuration indicates an invalid slot format for one or moreslots.

18. The method of any preceding clause, further comprising selecting apattern for one or more attributes of the modified child DU resourceconfiguration, wherein the pattern indicates a resource type for a setof symbols and slots.

19. The method of any preceding clause, further comprising:

receiving, by parent DU from the CU, a slot format to enable the parentDU to implicitly determine a switch type to allow the child node tocommunicate with a second parent DU; and

determining one or more guard symbols based on the slot format, whereinthe slot format corresponds to a valid format indicating to the parentDU to provide the one or more guard symbols for the child node duringswitching from the parent DU to a second parent DU.

20. The method of any preceding clause, wherein the modified child DUresource configuration indicates an invalid slot format for one or moreslots and includes one or more slots indicated as hard resources to theparent DU to indicate to the parent DU that the child node will not haveany communication with children nodes of the child node or anotherparent DU.

21. The method of any preceding clause, wherein the modified child DUresource configuration indicates an invalid slot format for one or moreslots and includes one or more slots indicated as not-availableresources to the parent DU to indicate to the parent DU that the childnode will be in communication with another parent DU.

22. The method of any preceding clause, wherein the modified child DUresource configuration includes a reserved resource type indicating to aparent-node that one or more resources are reserved and unavailable forthe parent-node to communicate with the child-node.

23. An apparatus for wireless communication, comprising:

a transceiver;

a memory configured to store instructions; and

one or more processors communicatively coupled with the transceiver andthe memory, wherein the one or more processors are configured to:

-   -   determine, by a central unit (CU), a configuration of        not-available (NA) resources for a parent node, wherein the NA        resources of the parent node correspond to a set of one or more        resources configured at the parent distributed unit (DU) as        being unavailable for uplink and downlink communications between        the parent DU and a child node, and    -   a first child DU resource configuration, wherein the child DU        resource configuration corresponds to a set of one or more        resources configured at the child node DU for uplink or downlink        communications between the child node and at least one child of        the child node;    -   modify, by the CU, the first child DU resource configuration to        create a modified child DU resource configuration configured to        provide an indication of the NA resources of the parent node;        and    -   send, by the CU to the parent DU, the modified child DU resource        configuration including the indication of the NA resources of        the parent node.

24. The apparatus of any preceding clause, wherein the one or moreprocessors are further configured to send, by the CU, the first child DUresource configuration to the child node.

25. The apparatus of any preceding clause, wherein the modified child DUresource configuration is different from the first child DU resourceconfiguration.

26. The apparatus of any preceding clause, wherein the modified child DUresource configuration includes an indication ofdownlink/uplink/flexible (D/U/F) resources and hard/soft/not-available(H/S/NA) resources.

27. An apparatus for wireless communication, comprising:

a transceiver;

a memory configured to store instructions; and

one or more processors communicatively coupled with the transceiver andthe memory, wherein the one or more processors are configured to:

-   -   receive, by a parent distributed unit (DU) from a central unit        (CU), a child DU resource configuration for a child node        including an indication of not-available (NA) resources, wherein        the NA resources correspond to a set of one or more resources        configured at the parent DU as being unavailable for uplink and        downlink communications between the parent DU and the child node        of the parent DU;    -   determine, by the parent DU, a set of resources corresponding to        the NA resources indicated in the child DU resource        configuration; and    -   refrain, by the parent DU, from communicating with the child        node within the NA resources based on the determining the set of        resources corresponding to the NA resources.

28. The apparatus of any preceding clause, wherein the child DU resourceconfiguration corresponds to a modified child DU resource configurationconfigured to indicate the NA resources to the parent DU.

29. The apparatus of any preceding clause, wherein the modified child DUresource configuration is different from a corresponding first child DUresource configuration provided to the child node.

30. The apparatus of any preceding clause, wherein the modified child DUresource configuration includes an indication ofdownlink/uplink/flexible (D/U/F) resources and hard/soft/not-available(H/S/NA) resources.

The above detailed description set forth above in connection with theappended drawings describes examples and does not represent the onlyexamples that may be implemented or that are within the scope of theclaims. The term “example,” when used in this description, means“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other examples.” The detailed description includesspecific details for the purpose of providing an understanding of thedescribed techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand apparatuses are shown in block diagram form in order to avoidobscuring the concepts of the described examples.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, computer-executable code or instructionsstored on a computer-readable medium, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with aspecially-programmed device, such as but not limited to a processor, adigital signal processor (DSP), an ASIC, a field-programmable gate array(FPGA) or other programmable logic device, a discrete gate or transistorlogic, a discrete hardware component, or any combination thereofdesigned to perform the functions described herein. Aspecially-programmed processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A specially-programmedprocessor may also be implemented as a combination of computing devices,e.g., a combination of a DSP and a microprocessor, multiplemicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The functions described herein may be implemented in hardware, software,or any combination thereof. If implemented in software executed by aprocessor, the functions may be stored on or transmitted over as one ormore instructions or code on a non-transitory computer-readable medium.Other examples and implementations are within the scope and spirit ofthe disclosure and appended claims. For example, due to the nature ofsoftware, functions described above can be implemented using softwareexecuted by a specially programmed processor, hardware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations. Moreover, the term “or” is intended to mean an inclusive “or”rather than an exclusive “or.” That is, unless specified otherwise, orclear from the context, the phrase, for example, “X employs A or B” isintended to mean any of the natural inclusive permutations. That is, forexample the phrase “X employs A or B” is satisfied by any of thefollowing instances: X employs A; X employs B; or X employs both A andB. Also, as used herein, including in the claims, “or” as used in a listof items prefaced by “at least one of” indicates a disjunctive list suchthat, for example, a list of “at least one of A, B, or C” means A or Bor C or AB or AC or BC or ABC (A and B and C).

Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation,computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code means in the form of instructions or data structures andthat can be accessed by a general-purpose or special-purpose computer,or a general-purpose or special-purpose processor. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the common principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Furthermore, although elements of the describedaspects and/or embodiments may be described or claimed in the singular,the plural is contemplated unless limitation to the singular isexplicitly stated. Additionally, all or a portion of any aspect and/orembodiment may be utilized with all or a portion of any other aspectand/or embodiment, unless stated otherwise. Thus, the disclosure is notto be limited to the examples and designs described herein but is to beaccorded the widest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method of wireless communications, comprising:receiving, by a parent distributed unit (DU) from a central unit (CU), amodified child DU resource configuration for a child node that ismodified from an initial child DU resource configuration provided to thechild node for communicating with at least one child of the child node,wherein the initial child DU resource configuration includes anindication of available and not-available (NA) resources forcommunications between the child node and the at least one child of thechild node, wherein the modified child DU resource configuration ismodified to indicate at least one NA resource of the NA resources asbeing unavailable for communications between the parent DU and the childnode; determining, by the parent DU, a set of resources corresponding tothe at least one NA resource indicated in the modified child DU resourceconfiguration; and refraining, by the parent DU, from communicating withthe child node within the at least one NA resource based on thedetermining the set of resources corresponding to the at least one NAresource.
 2. The method of claim 1, wherein the modified child DUresource configuration includes an indication ofdownlink/uplink/flexible (D/U/F) resources and hard/soft/not-available(H/S/NA) resources.
 3. The method of claim 1, wherein the modified childDU resource configuration includes one or more symbols including asymbol corresponding to the at least one NA resource indicated as a hardresource to the parent DU.
 4. The method of claim 1, wherein themodified child DU resource configuration indicates an invalid slotformat for one or more slots corresponding to the at least one NAresource.
 5. The method of claim 1, further comprising selecting apattern for one or more attributes of the modified child DU resourceconfiguration, wherein the pattern indicates a resource type for a setof symbols and slots.
 6. The method of claim 1, further comprising:receiving, by parent DU from the CU, a slot format to enable the parentDU to implicitly determine a switch type to allow the child node tocommunicate with a second parent DU; and scheduling one or more guardsymbols for the child node based on the slot format, wherein the slotformat corresponds to a valid format indicating to the parent DU toprovide the one or more guard symbols for the child node duringswitching from the parent DU to a second parent DU.
 7. The method ofclaim 1, wherein the modified child DU resource configuration indicatesan invalid slot format for one or more slots corresponding to the atleast one NA resource and includes one or more slots indicated as hardresources to the parent DU to indicate to the parent DU that the childnode does not communicate with children nodes of the child node oranother parent DU.
 8. The method of claim 1, wherein the modified childDU resource configuration indicates an invalid slot format for one ormore slots corresponding to the at least one NA resource and includesone or more slots indicated as not-available resources to the parent DUto indicate to the parent DU that the child node communicates withanother parent DU.
 9. The method of claim 1, wherein the modified childDU resource configuration includes a reserved resource type indicatingto the parent DU that one or more resources corresponding to the atleast one NA resource are unavailable for the parent DU to communicatewith the child node.
 10. An apparatus for wireless communication,comprising: a transceiver; a memory configured to store instructions;and one or more processors communicatively coupled with the transceiverand the memory, wherein the one or more processors are configured to:receive, by a parent distributed unit (DU) from a central unit (CU), amodified child DU resource configuration for a child node that ismodified from an initial child DU resource configuration provided to thechild node for communicating with at least one child of the child node,wherein the initial child DU resource configuration includes anindication of not-available (NA) resources for communications betweenthe child node and the at least one child of the child node, wherein themodified child DU resource configuration is modified to indicate atleast one NA resource of the NA resources as being unavailable forcommunications between the parent DU and the child node; determine, bythe parent DU, a set of resources corresponding to the at least one NAresource indicated in the modified child DU resource configuration; andrefrain, by the parent DU, from communicating with the child node withinthe at least one NA resource based on the determining the set ofresources corresponding to the at least one NA resource.
 11. Theapparatus of claim 10, wherein the modified child DU resourceconfiguration includes an indication of downlink/uplink/flexible (D/U/F)resources and hard/soft/not-available (H/S/NA) resources.
 12. Theapparatus of claim 10, wherein the modified child DU resourceconfiguration includes one or more symbols including a symbolcorresponding to the at least one NA resource indicated as a hardresource to the parent DU.
 13. The apparatus of claim 10, wherein themodified child DU resource configuration indicates an invalid slotformat for one or more slots corresponding to the at least one NAresource.
 14. The apparatus of claim 10, wherein the one or moreprocessors are further configured to select a pattern for one or moreattributes of the modified child DU resource configuration, wherein thepattern indicates a resource type for a set of symbols and slots. 15.The apparatus of claim 10, wherein the one or more processors arefurther configured to: receive, by parent DU from the CU, a slot formatto enable the parent DU to implicitly determine a switch type to allowthe child node to communicate with a second parent DU; and schedule oneor more guard symbols for the child node based on the slot format,wherein the slot format corresponds to a valid format indicating to theparent DU to provide the one or more guard symbols for the child nodeduring switching from the parent DU to a second parent DU.